Trailer maneuvering mechanism

ABSTRACT

A trailer drive wheel assembly for close quarter maneuvering of the trailer on which it is mounted. The assembly has an electric motor powered by a battery connected to the motor by a reversible switch. The motor is connected by drive means to a maneuvering wheel which can be raised and lowered between a traveling position and a working position by a retractable mounting means that is mounted on the underside of the trailer.

United States Patent [191 Wollenburg [451 Dec. 18,1973

1 1 TRAILER MANEUVERING MECHANISM [76] Inventor: John G. Wollenburg, 410Clinton Ave, Oak Park, 111.

[22] Filed: June 30, 1972 [21] Appl. No.: 268,033

[52] U.S. Cl. 180/14 A, 180/1 AW. 180/15. 180/19 [51] Int. Cl B62d 13/06[58] Field of Search 180/15, 1 AW, 11, 180/14 A, 12, 21, 22,19

[56] References Cited UNITED STATES PATENTS 3,705.638 12/1972 Shock180/11 X 3,690,397 9/1972 Parker 180/19 R X 2,778,181 1/1957 Gray 180/15X Kimball 180/12 Rabjohn 180/19 R X Primary Examiner-Evon C. BlunkAssistant ExaminerBruce H. Stoner, Jr. A1mrne v.loseph G. Werner et a1.

[57] ABSTRACT A trailer drive wheel assembly for close quartermaneuvering of the trailer on which it is mounted. The assembly has anelectric motor powered by a battery connected to the motor by areversible switch. The motor is connected by drive means to amaneuvering wheel which can be raised and lowered between a travelingposition and a working position by a retractable mounting means that ismounted on the underside of the trailer.

3 Claims, 3 Drawing Figures TRAILER MANEUVERING MECHANISM BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention pertains to meansfor maneuvering and propelling trailers in close quarters when there isnot sufficient room for a towing vehicle to be attached to the trailer.

2. Description of the Prior Art It is well known that trailers which arepulled by a drawbar or tongue are difficult to manuever in closequarters, especially when backing the towing vehicle. Oftentimes thereis not sufficient room to maneuver the trailer with the towing vehicleand the trailer must be disconnected from the vehicle in order to pushor pull the trailer to a parked position. It is extremely difficult tomove very heavy trailers by the use of man power alone. What is neededis an independent power-driven system that can be easily engaged anddisengaged and which will provide means to drive the trailer so that theoperator only has to work the controls and steer the trailer, but doesnot have to push or pull the trailer himself.

SUMMARY OF THE INVENTION Generally, my invention comprises apower-driven maneuvering wheel that can be retained in a raisedtraveling position when the trailer is being transported and loweredinto a working position to supply a power drive when the trailer isdisconnected from a towing vehicle and is to be maneuvered by hand.

An object of my invention is to provide an independent drive system fora trailer for close-quarter maneuvering. Another object of my inventionis to provide a trailer-drive system that is mounted on the trailer andis integral therewith so that a separate drive system does not also haveto be carried; A still further object of my invention is to provide atrailer-drive system that can be operated by one man who can bothoperate the trailer drive system controls and steer the trailer.

These and otherobjects of my invention, which will be apparent from thedescription and drawings, are accomplished by my trailer-drive systemwhich has a maneuvering wheel powered by an electric motor. The systemhas a means for retracting the wheel to a raised traveling position orextending it to a lowered working position. When extended down into thelower working position, the wheel is in contact with the surface onwhich the trailer rests and, by means of the reversible motor, is drivenso that the motor and maneuvering wheel provide a power-drive system formoving the trailer in either a forward or reverse direction. The switchfor controlling the motor in either the forward or reverse direction islocated near the drawbar or tongue of the trailer so that the operatorwho is steering the trailer by means of the drawbar can also control thepower drive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a trailer vanwith the side of the trailer partially cut away to show how my trailerdrive system is mounted and shows the maneuvering wheel and drawbarsupport in its retracted position.

FIG. 2 is an enlarged side view with the trailer substantially cut awayand showing the maneuvering wheel and drawbar support both in theirlowered working positions.

FIG. 3 is an isometric view of a portion of my trailerdrive system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now more particularlyto the drawings, a trailer 11 having a drawbar 12 extending therefromwith a trailer hitch 13 at the end of the drawbar is shown. Runningwheels located beneath the trailer and remote from the drawbar 12provide mobile support means for the trailer. My retractabletrailer-drive system is shown mounted on the underside of the trailergenerally as 13. It consists generally of a retractable maneuveringwheel 14 which is driven by a reversible electric motor 15 that in turnis powered by an electric source 16. The maneuvering wheel 14 ispositioned adjacently in front of the running wheels near the preferredcenter of gravity for a two-wheel or tandemwheel trailer. A threeposition switch 17 is mounted to the trailer in the vicinity of thedrawbar or on the drawbar and connects the motor and electric source bywiring, well known to those skilled in the art, and which is generallyshown as 18.

The electric power source 16 that is shown is preferably an electricstorage battery so that the trailer drive system is completely integralwith the trailer and independent from any outside source of energy.However it is recognized that an external power source could be used.For instance, by means of long extension cords, the system could beconnected to an external AC circuit and by means of A/C-D/C transformersdrive the motor 15. As'another alternative, similarly by using longextension cords, the motor could be driven off of a BIG power suppliedby the vehicle which towed the trailer to the place where it is to beparked.

Electric motor 15 is preferably a reversible motor so that it can be runin either a forward or a reverse direction and thereby the trailer canbe moved in either a forward or a reverse direction by means of thedrive system. In the preferred embodiment the motor used is a gear motorin order to reduce the rotating speed of the means driving themaneuvering wheel. It has been found that a gear motor having a worm andgear arrangement to accomplish the reduction is preferable, but the gearreduction could also be accomplished by a gear to gear arrangement andany other suitable reduction means that are well known by those skilledin the art. The switch 17 has forward, off and reverse positions and asshown is located on the front end of the trailer. The operator cantherefore control the direction of the trailer by the drawbar and at thesame time have the switch control at his fingertips in order to eitherstop the trailer-drive system or reverse its direction. For trailerswith a longer drawbar so that an operator standing near the hitch end ofthe trailer would be too far away from the switch, the switch 17 can belocated on the drawbar at a convenient distance from the hitch end ofthe bar.

The maneuvering wheel 14 can consist of more than one wheel as shown inFIG. 3 where there are two wheels, but it has been found that one wheelwill perform satisfactorily. The maneuvering wheel 14 is connected tothe motor 15 by a drive means generally shown as 19. I prefer to use agear chain arrangement since a chain with removable links can easily bereplaced, lengthened or shortened without having to remove any otherparts from the driving system. As

shown, a chain is axially connected to the wheel 14 by a sprockt 21.Similarly the chain is axially connected to the motor 15 by anothersprocket mounted on the axle 22 of the motor 15. By varying the sizes ofthe sprocket 21 connected to the axle of a wheel 14 and the sprocketconnected to the axle 22 of the motor 15 further gear reduction can beaccomplished if necessary. For additional rigidity, a bracket 23supports the axle 22 connecting the motor sprocket to the drive motor.This bracket 23 may not be necessary depending on the size of the axle22 and the twisting torque pressure that may be developed between themotor and the maneuvering wheel. A bracket 24 axially engages and holdsthe maneuvering wheel 14 in spaced relationship with the motor axle 22so that the proper tension can be maintained in the drive means 19.

Generally shown at 25 is a retractable mounting means for raising andlowering the maneuvering wheel 14 between the raised traveling position,in which it is shown in FIG. 1, and its lowered working position, inwhich it is shown in FIG. 2. This retractable mounting means includesthe previously described bracket 24, which provides a first suspensionarm for the maneuvering wheel. The rearward end of the bracket 24 ispivotally engaged at a fixed location on the underside of the trailer,which location is preferably provided by the motor axle 22, asillustrated in the drawings. In addition, the mounting means includes aU-shaped bracket 26 axially engaged with the maneuvering wheel 14, aU-shaped bracket 28 which is pivotally connected to a threaded cylinder29, and a bar 27 which connects the U-shaped brackets 26 and 28. Thebracket 26, bar 27 and bracket 28 together comprise a second suspensionarm for the maneuvering wheel 14. The ends of said first and secondsuspension arms which are respectively connected to the motor axis 22and the cylinder 29 will sometimes be referred to herein as theseparated ends of the arms.

The threaded cylinder 29 comprises a transfer member for applying alinear force to the retractable mounting means to force the maneuveringwheel 14 up or down as required. An extension means 30 is mounted to thetrailer 11 and connects to the cylinder transfer member 29 of theretractable mounting means 25 for raising and lowering mounting means25. As shown in the drawings the preferred extension means 30 is acontinuous screw or worm, the threaded end of which extends through thethreaded cylinder 29. This screw is connected to the trailer andsupported by the brackets.

shown as 31 in the drawing. When the worm 30 is turned by means of thecrank 32 the threaded cylinder transfer member 29 will be movedlongitudinally along the threaded portion of the worm. This will forcethe separated end of the second suspension arm 26, 27 and 28, which isconnected to the transfer member 29, toward or away from the separatedend of the first suspension arm 24, which is pivotally engaged at thefixed location of the motor axle 22. As the separated end of the secondsuspension arm is forced toward the separated end of the firstsuspension arm 24 by the transfer member 29, the ends of the suspensionarms which are axially engaged with the maneuvering wheel 14 will forcethe maneuvering wheel 14 downwardly into driving engagement with theground or other trailer supporting surface, as shown in FIG. 2. As theseparated ends of the suspension arms are forced apart by the transfermember 29, the maneuvering wheel 14 will be raised to its travelingposition shown in FIG. 1. Other alternatives to a worm could be used forthe extension means 30, such as a sliding bar to which the transfermember 29 would be fixedly connected. By sliding the bar and transfermember forward or aft the retractable mounting means would be raised orlowered respec tively.

A pivotal support 33 is shown mounted on the hitch end of the drawbar12. The support 33 has a wheel 34 mounted to a substantially verticalrod 35 by means of a bracket 36 axially connected to the wheel 34. Therod 35 extends through the drawbar 12 and a crank or steering wheel 37is mounted on the upper end of the rod 35 so that the wheel 34 can beturned by the operator. Thus the operator can use the pivotal support 33to steer the trailer while propelling it by means of my trailer-drivesystem. This pivotal support 33 can be raised to a traveling positionsuch as is shown in FIG. 1 and lowered to a working position as shown inFIG. 2. This can be accomplished in a number of ways. For example, therod 35 could be a worm or screw that is raised and lowered by turning itwith the crank or wheel 37. When it is lowered into the working positionit could be lowered far enough so that the slight turning that is donewhen using the wheel 34 to steer the trailer would not be enough toraise the wheel above the level of contact with the ground. As analternative the rod 35 could have apertures through it, and when thesupport is raised to its traveling position, as shown in FIG. 1, a pincould be placed through the aperture above the tongue so that the rodcould not drop to its lowered position. When it is desired to move thesupport to its working position, as shown in FIG. 2, the pin is removed,the wheel lowered, and then the pin placed through the aperture at theunderside of the drawbar 12 so that the rod 35 could not be raised awayfrom its lowered working position. The pin acts as a stopper in eitherdirection, as desired. It is understood that this invention is notconfined to the particular construction, arrangement of parts, andmaterials herein illustrated and described for exemplification of theprinciples of the invention, but embraces all such modified formsthereof as come within the scope of the following claims.

I claim:

1. A retractable trailer-drive system for close-quarter maneuvering incombination with a trailer having a drawbar at its front end and runningwheels remote from the drawbar, said trailer drive system comprising:

a. a reversible electric motor mounted on the underside of said trailer,

b. means for providing a source of electric current to said motor,

c. a maneuvering wheel supported beneath the underside of said trailerat a position remote from the drawbar and spaced adjacently in front ofthe running wheels,

. means connecting said maneuvering wheel to said motor for driving saidmaneuvering wheel,

e. retractable mounting means secured to the underside of said trailerfor raising and lowering said maneuvering wheel between a raisedtraveling position and a lowered working position, said mounting meanshaving first and second suspension arms each having one end thereofaxially engaged with said maneuvering wheel, said first suspension armhaving a separated end.pivotally engaged on the underside of saidtrailer, and said second suspension arm having a separated end pivotallyengaged with a transfer member movably mounted on the underside of saidtrailer,

f. extension means mounted to said trailer for engaging and moving saidtransfer member toward said first suspension arm separated end to forcethe ends of said suspension arms engaged with said maneuvering wheeldownwardly, and for moving said transfer member away from said firstsuspension arm sparated end to lift the suspension arm ends engaged withsaid maneuvering wheel upwardly, and

g. a pivotal support depending from said drawbar for said screw isrotated.

1. A retractable trailer-drive system for close-quarter maneuvering incombination with a trailer having a drawbar at its front end and runningwheels remote from the drawbar, said trailer drive system comprising: a.a reversible electric motor mounted on the underside of said trailer, b.means for providing a source of electric current to said motor, c. amaneuvering wheel supported beneath the underside of said trailer at aposition remote from the drawbar and spaced adjacently in front of therunning wheels, d. means connecting said maneuvering wheel to said motorfor driving said maneuvering wheel, e. retractable mounting meanssecured to the underside of said trailer for raising and lowering saidmaneuvering wheel between a raised traveling position and a loweredworking position, said mounting means having first and second suspensionarms each having one end thereof axially engaged with said maneuveringwheel, said first suspension arm having a separated end pivotallyengaged on the underside of said trailer, and said second suspension armhaving a separated end pivotally engaged with a transfer member movablymounted on the underside of said trailer, f. extension means mounted tosaid trailer for engaging and moving said transfer member toward saidfirst suspension arm separated end to force the ends of said suspensionarms engaged with said maneuvering wheel downwardly, and for moving saidtransfer member away from said first suspension arm sparated end to liftthe suspension arm ends engaged with said maneuvering wheel upwardly,and g. a pivotal support depending from said drawbar for supporting andsteering the front end of said trailer.
 2. The trailer-drive system ofclaim 1 wherein said means for providing a source of electric current tosaid motor comprises a battery mounted on said trailer and a switchconnecting said motor and said battery.
 3. The trailer-drive system inclaim 1 wherein the extension means for moving the transfer member is acontinuous screw mounted for rotation on the underside of the trailer,said screw having a crank and a portion threadedly engaged with thetransfer member to move said transfer member longitudinally on saidscrew when said screw is rotated.